Yes, there was a whole storyline of Bonnie Lockhart using Mimi's baby and pretending it was her own child, fathered by Lucas, so she could stay out of jail for switching places with Adrienne and putting poor Adrienne in prison. The truth came out that the child (called Baby Bonnie at that point) was really Mimi's baby, Emily, from a one-night hookup with Rex. That brought Rex and Sarah's engagement to a screeching halt, at first. Later he admitted to also having sex with Sarah's half sister, Noel Curtis (we didn't see her) and that caused another meltdown, but they eventually reconciled and got married. Later, she broke up with Rex to be with bad twin, Father Sourpuss (Eric).
